Internal combustion engine



April 1939- G. K. sfEwARD 2,153,598

INTERNAL COMBUS T ION ENGINE Filed April 2, 1936 INVENTOR. George K. SfeWard.

Patented Apr. 11, 1939 UNITED STATES PATENT OFFICE Application April 2,

19 Claims.

This invention relates to improvements in internal combustion engines,and especially to means and the method of. igniting and burning fuel gasor combustion mixture therein to control detonation. I

Heretofore detonation, which is objectionable, has been controlled byproducing turbulence, or in other words, violent mixing of the powercharge. This has been accomplished in one instance by specialconstruction of the intake manifold, in another instance by specialconstruction of the cylinder head. In both of these instances, however,the turbulence period precedes the ignition of the charge, and to such adegree that the turbulence has been considerably reduced prior to actualignition of the charge.

An object of the present invention is to produce turbulence of thecharge by and during the ignition thereof to thus initiate turbulenceand enhance it during the combustion period.

To this end the method of this invention consists in preparing acomparatively small quantity of gas consisting of a higher percentage ofoxygen than is contained in the gas of the power charge,

and preparing another small quantity of gas having a still higherpercentage of oxygen than that contained in the first mentionedquantity, then igniting the first quantity of gas, using the firethereof to ignite the power charge by piercing it with a plurality offlame torches of high speed ratio directed from the first quantity ofburning gas and extending it in difierent directions into the powercharge to initiate turbulent combustion thereof, and igniting theauxiliary charge or second quantity of gas and utilizing it to enhancethe torch flame propagation and projected, turbulent combustioninitiated by the first charge.

The means to carry out the present invention 0 includes a primarychamber in which the first charge of gas is ignited, and a, secondarychamber in which charge of high percentage of oxygen is fired, thesechambers being independent of each other and independent of the usualcom- 45 bustion chamber. The primary ignition chamher. and the secondaryignition chamber are herein shown as included in the spark plug.

Features of the invention also relate to the spark plug.

Other features and advantages will hereinafter appear.

' In the drawing which forms part of fication:

Fig. 1 is a central section through the greater the speci- 55 part of aspark plug embodying the invention;

1936, Serial No. 72,223

Fig. 2 is a vertical section of a portion of a motor showing the sparkplug applied thereto;

Fig. 3 is a detail sectional view of the valve for air intake of thespark plug;

, Fig. 4 is a. face view of the check element of the air intake valve;

Fig. 5 is a sectional, top plan view taken on the line 5-5 of Fig. 1;

Fig. 6 is a view of a portion of the spark plug, partly in section, thesection being taken on the line 6--6 of Fig. 5; and

' Fig. 7 is a view similar to Fig. 6, the section being taken on theline 'l-'I of Fig. 5.

Similar reference characters represent similar parts throughout theseveral views.

The spark plug includes a casing or shell or body III in which there isheld an insulator II by a sleeve nut I2 threaded into the upper end ofthe shell I, gaskets l3 and I 4 being interposed between shoulders I5and I6 of the shell and nut respectively, and cooperative shoulders I!and iii of the insulator.

The shell I0 is provided with a threaded portion I9, to readily screwinto a threaded hole 20 in the water jacket 2|, of the motor casing 22,until it is tightly seated against a shoulder 23 formed on an annularportion 24 of the shell, the usual gasket being used under the shoulder'23 of the spark plug. A center electrode 25 and a ground electrode 26are provided to produce the electric are between them.

Upon the down stroke of a piston 21 in a, cylinder 28 the intake valvehead 29 israised, in the usual well known manner, and a fresh charge offuel gas is drawn into the combustion chamber 30. At the same time airis drawn through a check valve 3| into a chamber 32, herein shown asformed in the spark plug. This supply of air clears the chamber 32 ofany carbon, lead, or dead gas and furnishes the chamber with a volume ofair. The volume of air taken in through the valve 3| may be slightlygreater than the capacity of the chamber 32 thus causing some of the airto pass into another chamber 33 in which the electrodes 25 and 26 arehoused, the chambers 32 and 33 communicating with each other through anannular passage 34 formed by the nose 35 of the insulator H and anannular shoulder 36 formed on the interior of the shell Ill.

During the succeeding compression stroke of the piston the fuel gas,taken into the combustion chamber, is compressed thus causing some of itto pass into chamber 33, through angularly disposed orifices 31 and acentral orifice 38 formed in the nose 39 of the shell l0, said nosebeing located inside the combustion chamber 30 and being clear of themotor casing. The plug shell remains at an approximate thermal balancethroughout the operation of the motor, and the .fuel gas passing throughorifices 31 and 33 is heated and its speed of flow increased, thusfinely atomizing and expanding it. This prepares a mixture in thechamber 33 which will burn with a speed much greater than that of thecombustion speed of the power charge in the combustion chamber 30.

The shell In is also provided with two canals 40 extending into it fromthe nose 39 and terminating in the near end of the chamber 32 wherebyfuel gas under compression is alsoadmitted to the chamber 32, but in asmaller percentage because of the air already in the chamber 32. The gasadmitted through the canals 40.

is highly atomized and thermally expanded and because of the highpercentage of oxygen of the charge in chamber 32, this charge which isunder compression, has a tremendously rapid burning ratio as compared tothe burning speed of the heavy power charge in the combustion chamber30, and its burning speed is also more rapid than that of thecharge inchamber 33 which has a smaller percentage of oxygen contained therein.

The charge in chamber 33 is ignited by a spark produced by theelectrodes 23 and 23 at the proper time in the cycle of operations ofthe motor. This ignites the charge in the primary chamber 33 which burnsat high speed, expands greatly and is projected, through the orifices 31and 33, in torches of flame throughout the power charge in thecombustion chamber 30, thus producing a condition of high speedprojected, turbulent combustion-reaching various portions of the powercharge-simultaneouslyand also progressively and extending to remoteparts of the combustion chamber. This causes a more uniform and rapidspread of the fire through the power charge, which results in combustionwhich is far superior to that heretofore produced in combustion chambersof internal combustion motors.

The burning of the charge in the chamber 33 also ignites the charge inchamber 32, and since the charge in chamber 32 has a high percentage ofoxygen and consequently burns with a burning speed which is much higherthan the ordinary speed of flame travel of ordinary combustion; itenhances the condition of projected, turbulent combustion initiated inthe ignition chamber 33.

Wall effect, or in other words the tendency of the walls to keep the gasin contact therewith or in close proximity thereto, from burning, isalso limited or greatly reduced by projected turbulent combustion.

From the foregoing it will be understood that the ignition starts in thechamber 33 at the electrodes 25 and 26. Fire is projected from both endsof the ignition chamber, downwardly and outwardly through the orifices31 and 33 in a plurality of torches of, high speed flame travel, intothe power charge in the 30, and upwardly into the Because of itspercentage of oxygen the charge in the ignition chamber 33 is of greaterburning speed than that of the power charge as herein before mentionedand is of slower burning speed than that of the charge in the enhancingchamber 32. This results in longer burning in the enhancing chamber 32.

ignition chamber 33 than in the chamber '32, and

this method of combustion chamber Briefly the electricspark ignites anespecially conditioned charge in primary chamber 33. The fire of thischarge ignites the more highly conditioned charge in secondary chamber32, and then the charges of both chambers 32 and 33 combine to projectcombustion, at a speed much higher than that of the combustion ofordinary fuel gas, into the power charge so as to produce intense,turbulent and progressive combustion simultaneously in various parts ofthe combustion chamber 30.

The consumed gas is exhausted from the cylinder, during the succeedingup stroke of the piston, in the usual manner, and a fresh charge issupplied to the combustion chamber, as above described, upon the nextdown stroke of the piston. It will be remembered that during the intakestroke of the piston air is drawn into the chambers 33 and'32 throughthe check valve 3|.

The nose 3301' the plug is out of direct contact with water jacket 2|and consequently its temperature is considerably higher than that of thewater jacket .and thus highly efilcient in conditioning the fuel gaswhich is forced through the canals 40 into the chamber 32 which haspreviously received one volume of air through valve 3 I. The fuel gaswhile passing through the canals 40 is thus heated sufiiciently toproduce ebulli-.

tion or flashing thus making the gas lighter or in other words reducingits density. As the gas advances in the canals its temperature risessomewhat and the temperature of the nose is caused to drop slightly bythe gas, thus producing an automatic thermal balance of the nose by gasregulation. The fuel gas which passes through the orifices 31 and 38 isalsoheated bythe nose 33.

Due to its construction, the nose practically eliminates the possibilityof oil contacting with the insulator, thus fouling of the plug, due tocarbon in the lubricating oil, or-to the iron conparts, is minimized.

The orifices 31 and 33 and the canals 40, in addition to serving tostimulate gas characteristics in chambers '32 and 33 also induce the gasto so influence various shell temperatures that the entire plug is givena semi-automatic thermal balance which varies advantageously to meetchanging speed and load conditions of the motor. This of course is in apredetermined ratio to the normal water jacket regulation.

It will be understood that since air is admitted to both chambers 32and33, but less in the latter chamber, and that fuel gas is admitted toboth of these chambers, to the one through canals 40 and to theotherthrough the orifices 31 and 38, that there are employed two systemsof carburation and that both of these are in the spark plug.

The shell I! is made quite thick at 4| so as to provide a quantity ofmetal whereby thermal equilibrium of the nose 33 is maintained. In otherwords the thick portion ll of the shell, because of its contact with thewater jacket 2|, keeps the nose from becoming too hot, whichmay'otherwise occur due to repeated firing, and.

portion 24 of the plug shell so that the air may tent therein, resultingfrom wear of the motor,

pass, through said aperture 44 and orifice 43, into a chamber 45containing a check element 46. The latter is provided on itshemispherical face 41 with a groove 48 through which the air may pass,in case the check element 46 seats itself against the face 45 to apassage 49 through which it is admitted to the chamber 32. normaloperation, while passing through this valve 3|, the air becomes heatedbeyond the flash point of the gas, thus preventing condensation of thegas in the chamber 32 while the air is mixing with said gas. Duringcompression stroke and fire stroke of the piston the check element 46 ofthe valve 3|, is forced against the inner end of the screw 42 to closethe orifice 43 thus preventing escape of the gas from the chamber 32. Itshould be understood that the air, taken in through the valve 3|, hassome effect of regulating the temperature of the insulator.

The valve screw 42 is adjustable about its axis so as to vary theposition of the orifice 43 with respect to aperture 44 in the shell thusvarying the quantity of air drawn into the plug to thus vary thepercentage of oxygen in the charge of the chamber 32 in accordance withthe work of the motor in which the spark plug is to be employed. Forexample in a high speed motor a greater percentage of oxygen is requiredin the gas mixture of chamber 32 than is required in a low speed heavyduty motor.

The charge in chamber 32 burns clean (with out soot or other deposit)and at terrific speed, and in addition to enhancing the conditions ofprojected, turbulent combustion started by the charge of chamber 33, ittends to purge chamber 33 of iron, carbon and lead and prevent foulingby any of these. It also has a cleaning effect on the exposed shellportions, within the combustion chamber, spark plug holes, and adjacentsurfaces. This makes for efficiency since it permits making the sparkunder the most favorable circumstances in chamber 33. This also givesthe electrodes at longer life and insures good motor performance aschanging spark characteristics influence motor performance less than 1in plugs of the ordinary type.

Practically all fuel gases in use today contain at least a, smallquantity of lead and this frequently causes lead fouling ofthe insulatorby I attaching itself to the insulator and frequently amalgamating withthe glaze thereon and thus breaking down the dielectric. This kind offouling has never been successfully overcome and in many instances hasnecessitated frequent cleaning of the plugs. The present invention,however, prevents lead fouling because of the plugs low thermal ratingcharacteristics and because of the frequent purging of the chambers 32and The end 35 of the insulator II is so located with respect to theopen end of the chamber 32 that a portion of the insulator is sweptclean of foreign matter by the passage of the burning fiame. oftremendous speed, and high pressure,

through the. annular passage 34 at each firing operation. This assistsin maintaining the necessary dielectric character of'the insulator. Thehigh speed fire moving through the passage 34 is also directed towardsthe electrodes 25 and 2B and tends to keep them clean and thermallybalanced. l 4

Because the electrodes are not depended upon to fire the power charge,butchiefiy to ignite the firing charge in chamber 33 the insulator ltmayIn a be designed to be cool enough to prevent the tendency of lead tocling to the insulator and thus assist to prevent lead fouling. Thisalso prevents one form of preignition, caused in other spark plugs whentheir insulators are over leaded.

It will be understood thatin each engine cycle there is athree phaseventilation of the spark plug by air, by gas and by flame toautomatically purge the chambers 32 and 33. breathing effect in thisspark plug as in others. Consequently smothering, which is produced byunburned gases usually resulting from wall effect in the combustionchamber, is eliminated. This ventilation also prevents wall effect inthe spark plug through increased internal turbulence.

Due to the purging by air no dead or unburned gas is left in the sparkplug cavities as in other types of spark plugs, thus eliminatingone'necessity for constructing spark plugs with a delicate thermalbalance which requires carefully selected installation according to theclassification.

Because of the arrangement of electrodes 25 and 23 with respect to theorifices 31 and 38 said electrodes may readily be cleaned by sand blastor other means, without taking the spark plug apart, in case it fouls.due to a deposit thereon which may result from failure to sparkresulting from some cause other than the spark plug itself. However,since the spark plug is composed of three principal pieces, shell, III,insulator, II, and nut, it may readily be taken apart if necessary.

The requirement of atomic stimulation at the electrodes 25 and 26 neednot be as greatyin the spark plug of this invention, as-that of otherspark plugs to produce motor efficiency and therefore the electrodes areless subject to crystallization which results in longer life of thespark plug than heretofore. I

' From the above it will be understood that detonation is controlled bya plurality of torches of high speed flame travel which pierce the powercharge in the combustion chamber and thus break up the unit frontadvance of flame propagation, or in other words, the tendency of a flameto grow in all directions, in unit formation, from a source, by startingcombustion in various locations in the combustion chambersimultaneously, which combustion grows with great turbulence throughoutthe entire'power charge. This simultaneous ignition in various regionsof the combustion chamber by the torches of high speed flame travel,also reduces localized hot spots which are objectionable because theyaggrevate detonation trouble. The turbulence produced by high speedprojected combustion in addition to limiting wall effect, also limitscondensation of the fuel gas which condensation eilects the lubricatingoil of the motor. It also helps to more adequately fire the heavy endsof the fuel charge. The'superior combustion produced by this inventionalso allows a. slightly later ignition timing without loss of motorperformance or efliclency.

'It will be understood that the spark plug of this invention isuniversal in thermal application to motor requirements because highspeed live flames are depended upon to fire the compare-- tively heavypower change in the cylinder instead of the spark from a delicatelybalanced and often misapplied, fixed, thermal rating plug as hereto-.

There is no itself to the heat ranges of various motors with out thesacrifice of motor emciency or fouling. In other words the same sparkplug may be used, under different conditions in various motors whereheretofore it has been necessary to use separate spark plugs ofdifferent design to meet the condition of the motor.

Having thus described the invention it will be further understood thatvariations may be resorted to without departing from the spirit of theinvention defined in the appended claims.

I claim:

1. The method of controlling detonation of a power charge in'an internalcombustion engine, which includes the preparation of two firing charges,auxiliary to the power charge, igniting one of the firing charges,utilizing the ignited charge to ignite the power charge and the otherfiring charge, and utilizing the last named firing charge to enhance theignition effect of the first ignited charge on the power charge.

2. The method of controlling detonation of a power charge in an internalcombustion engine, which includes the preparation of a primary chargeconsisting of a mixture of fuel gas and an ingredient having a higherpercentage of oxygen than that contained in the power charge, and asecondary charge consisting of a mixture of fuel gas and a higherpercentage of oxygen than that contained in the primary charge, ignitingthe primary charge to thereby start turbulent combustion of the powercharge, igniting the secondary charge by the fire of the primary charge,and utilizing the fire of the secondary charge toenhance the turbulentcondition started by the primary charge.

3. The method of controlling detonation of a power charge in an internalcombustion engine which includes the preparation of a primary chargeconsisting of a mixture of fuel gas and an ingredient having a higherpercentage of oxygen than that contained in the power charge, and asecondary charge consisting of a mixture of fuel gas of a higherpercentage of oxygen than that contained in the primary charge, ignitingthe primary charge, dividing the fire of the ignited charge into aplurality of torches of fiame to thereby ignite the power charge in aplurality of places to start turbulent combustion of the power charge,igniting the secondary charge by the fire of the primary charge, andutilizing the burning secondary charge ,to increase the travel of thedivided fire to thus enhance the turbulent com.- bustion started in thepower charge,

4. The method of controlling detonation of a power charge inan internalcombustion {engine which includes supplying fuel gas and air separately,compressing the fuel gas and mixing some with the air and forming twoseparate charges with higher percentage of oxygen in one than in theother and both with a higher percentage of oxygen than the fuel gas ofthe power charge, igniting the charge containing the lower percentage ofoxygen, igniting the power charge by the fire of the ignited charge,igniting the charge containing the higher percentage of oxygen toproduce fire of high speed flame travel, and utilizing this fire of highspeed flame travel to enhance the effect of the fire of the previouslyignited one of said two charges.

5. In a spark plug for an internal combustion engine, the combination ofmeans forming a primary chamber, means forming a secondary chamber,means to admit air from the exterior of said plug into the said chambersduring each intake of the engine, means to admit fuel gas into theprimary chamber from said engine, means to admit fuel gas into thesecondary chamber from said engine, and electrodes in the primarychamber to ignite the charge therein to thereby ignite a power chargeand also ignite the charge in the secondary chamber. 6. In a spark plug,the combination of two elements, namely a shell and an insulator, a noseat one end of said shell, the insulator extending into said shell fromthe other end thereof, a shoulder on one of said elements, said shoulderforming with the other element two chambers with a. narrow passagebetween them, an air inlet valve associated with one of said chambers,and electrodes in the other chamber, said nose having apertures thereinextending into both chambers.

7. In an internal combustion engine having a combustion chamber intowhich may be introduced a power charge, the combination of means to forman initial firing charge, means to form a secondary firing charge, andmeans to ignite the initial charge to produce fire to ignite the powercharge and the secondary firing charge.

8. In a spark plug for an internal combustion engine, the combination ofa shell, and an air intake valve in said shell, said valve including ascrew having an aperture extending into it from the side thereof and outfrom, the inner end of said screw, said shell having an aperturecommunicating with the aperture in said screw, said screw beingadjustable about its axis to set the aperture therein with respect tothe aperture in the shell to thus regulate the quantity of air to betaken in through said valve.

9. In a spark plug for an internal combustion engine, the combination ofa shell having a chamber in its wall, and an air intake valve in saidchamber, said valve including a screw having an aperture extendingthrough it to the inner face thereof through which air is admitted, anda check element supported independently of said screw, said checkelement being operable by pressure from within the plug to engage saidinner end of said screw to close the aperture.

10. The method of controlling detonation of the power charge in aninternal combustion engine which includes the preparation of a primarycharge consisting of a mixture of fuel gas and an ingredient having ahigher percentage of oxygen than that contained in the power charge, anda secondary charge consisting of a mixture of fuel gas and a higherpercentage of oxygen than that contained in the primary charge, ignitingthe primary charge to thereby start turbulent combustion of a powercharge, igniting the secondary charge by the fire of the primary charge,and separating the fire of the primary charge into a plurality oftorches having high speed fiame travel to penetrate the power charge.

11. In a spark plug for an internal combus tion engine, the combinationof a shell, an insulator extending into said shell and forming therewithtwo communicating chambers with a narrow passage between them, meanswhereby fresh air may be admitted into one of said chambers, said shellhaving apertures therein extending from both chambers and opening intothe combustion chamber served by the spark plug, and electrodes in oneof the communicating chambers.

12. The method of controlling detonation of the power charge in.aninternal combustion engine, which includes the ignition of a primaryauxiliary charge to ignite the power charge and initiate turbulencethereof utilizing the fire oi the primary charge to ignite a secondauxiliary charge, and then utilizing a second auxiliary charge toenhance the ignition effect of the pri-, mary auxiliary charge to thusincrease the turbulence initiated in the power charge by the primaryauxiliary charge.

13. The method of controlling detonation oi the power charge in aninternal combustion engine, which includes simultaneous ignition andproduction of turbulence oi the power charge,

' and then enhancing the turbulence of the power charge during theremainder of its combustion period.

14. time method of producing turbulent combustion or a power charge inan internal combustion engine, which consists in propagating a series oftorch like flames through the power charge, and increasing the travel ofthe flames aiter they have been initiated and during the combustionperiod of the power charge.

15. The method 01 controlling detonation oi the iuel charge in aninternal combustion engine, which consists in igniting the power chargeand then enhancing the travel 0! the fire through the power charge.

16. In an internal combustion engine having a combustion chamber, thecombination of means forming two auxiliary chambers having a constrictedcommunicating passage between them, an air inlet valve associated withone of said auxiliary chambers, ignition means in the other auxiliarychamber, and means forming apertures extending from the combustionchamber,into both auxiliary chambers.

17. The method oi igniting the power charge of an internal combustionengine which consists in igniting a plurality oi firing charges insequence to each other and thereby creating a eumulative expulsiveeilect serving to enhance the ignition eiIect of the combined firingcharges on the power charge.

l8. Ina spark plug for an internal combustion I engine, said spark plughaving a shell, said shell 7 having an air passage therein, and anadjustable device in said shell and having an aperture therein, saiddevice being settabie to adjust its aperture relatively to said passageto regulate the quantity of air through said aperture independently ofengine pressure conditions.

19. In an internal combustion engine having a combustion chamber intowhich may be introduced a power charge, the combination of means inwhich is formed an initial firing charge, means in which is -formed asecondary charge, there being a constricted communicating passage fromone to the other of said means, and means to ignite the initial chargeindependently of the secondary charge to produce fire to thereby ignitethe power charge and also ignite the secondary charge through saidcommunicating passage.

GEORGE K. STEWARD.

